在Scala中解析命令行参数的最佳方法是什么? 我个人更喜欢一些不需要外部罐子的轻量级的东西。
相关:
我如何解析Java中的命令行参数? c++有哪些参数解析器库? 在c#中解析命令行参数的最佳方法
在Scala中解析命令行参数的最佳方法是什么? 我个人更喜欢一些不需要外部罐子的轻量级的东西。
相关:
我如何解析Java中的命令行参数? c++有哪些参数解析器库? 在c#中解析命令行参数的最佳方法
当前回答
freecli
package freecli
package examples
package command
import java.io.File
import freecli.core.all._
import freecli.config.all._
import freecli.command.all._
object Git extends App {
case class CommitConfig(all: Boolean, message: String)
val commitCommand =
cmd("commit") {
takesG[CommitConfig] {
O.help --"help" ::
flag --"all" -'a' -~ des("Add changes from all known files") ::
O.string -'m' -~ req -~ des("Commit message")
} ::
runs[CommitConfig] { config =>
if (config.all) {
println(s"Commited all ${config.message}!")
} else {
println(s"Commited ${config.message}!")
}
}
}
val rmCommand =
cmd("rm") {
takesG[File] {
O.help --"help" ::
file -~ des("File to remove from git")
} ::
runs[File] { f =>
println(s"Removed file ${f.getAbsolutePath} from git")
}
}
val remoteCommand =
cmd("remote") {
takes(O.help --"help") ::
cmd("add") {
takesT {
O.help --"help" ::
string -~ des("Remote name") ::
string -~ des("Remote url")
} ::
runs[(String, String)] {
case (s, u) => println(s"Remote $s $u added")
}
} ::
cmd("rm") {
takesG[String] {
O.help --"help" ::
string -~ des("Remote name")
} ::
runs[String] { s =>
println(s"Remote $s removed")
}
}
}
val git =
cmd("git", des("Version control system")) {
takes(help --"help" :: version --"version" -~ value("v1.0")) ::
commitCommand ::
rmCommand ::
remoteCommand
}
val res = runCommandOrFail(git)(args).run
}
这将产生以下用法:
使用
其他回答
斯科普特/斯科普特
val parser = new scopt.OptionParser[Config]("scopt") {
head("scopt", "3.x")
opt[Int]('f', "foo") action { (x, c) =>
c.copy(foo = x) } text("foo is an integer property")
opt[File]('o', "out") required() valueName("<file>") action { (x, c) =>
c.copy(out = x) } text("out is a required file property")
opt[(String, Int)]("max") action { case ((k, v), c) =>
c.copy(libName = k, maxCount = v) } validate { x =>
if (x._2 > 0) success
else failure("Value <max> must be >0")
} keyValueName("<libname>", "<max>") text("maximum count for <libname>")
opt[Unit]("verbose") action { (_, c) =>
c.copy(verbose = true) } text("verbose is a flag")
note("some notes.\n")
help("help") text("prints this usage text")
arg[File]("<file>...") unbounded() optional() action { (x, c) =>
c.copy(files = c.files :+ x) } text("optional unbounded args")
cmd("update") action { (_, c) =>
c.copy(mode = "update") } text("update is a command.") children(
opt[Unit]("not-keepalive") abbr("nk") action { (_, c) =>
c.copy(keepalive = false) } text("disable keepalive"),
opt[Boolean]("xyz") action { (x, c) =>
c.copy(xyz = x) } text("xyz is a boolean property")
)
}
// parser.parse returns Option[C]
parser.parse(args, Config()) map { config =>
// do stuff
} getOrElse {
// arguments are bad, usage message will have been displayed
}
上面生成了以下用法文本:
scopt 3.x
Usage: scopt [update] [options] [<file>...]
-f <value> | --foo <value>
foo is an integer property
-o <file> | --out <file>
out is a required file property
--max:<libname>=<max>
maximum count for <libname>
--verbose
verbose is a flag
some notes.
--help
prints this usage text
<file>...
optional unbounded args
Command: update
update is a command.
-nk | --not-keepalive
disable keepalive
--xyz <value>
xyz is a boolean property
这是我目前使用的。使用干净,没有太多包袱。 (免责声明:我现在维护这个项目)
我刚刚在scalac的scala.tools.cmd包中找到了一个广泛的命令行解析库。
参见http://www.assembla.com/code/scala-eclipse-toolchain/git/nodes/src/compiler/scala/tools/cmd?rev=f59940622e32384b1e08939effd24e924a8ba8db
Here's a scala command line parser that is easy to use. It automatically formats help text, and it converts switch arguments to your desired type. Both short POSIX, and long GNU style switches are supported. Supports switches with required arguments, optional arguments, and multiple value arguments. You can even specify the finite list of acceptable values for a particular switch. Long switch names can be abbreviated on the command line for convenience. Similar to the option parser in the Ruby standard library.
我建议使用http://docopt.org/。有一个scala端口,但是Java实现https://github.com/docopt/docopt.java工作得很好,而且似乎维护得更好。这里有一个例子:
import org.docopt.Docopt
import scala.collection.JavaConversions._
import scala.collection.JavaConverters._
val doc =
"""
Usage: my_program [options] <input>
Options:
--sorted fancy sorting
""".stripMargin.trim
//def args = "--sorted test.dat".split(" ").toList
var results = new Docopt(doc).
parse(args()).
map {case(key, value)=>key ->value.toString}
val inputFile = new File(results("<input>"))
val sorted = results("--sorted").toBoolean
我的方法基于上面的答案(来自dave4420),并试图通过使其更通用来改进它。
它返回所有命令行参数的映射[String,String] 你可以查询你想要的特定参数(例如使用.contains)或将值转换为你想要的类型(例如使用toInt)。
def argsToOptionMap(args:Array[String]):Map[String,String]= {
def nextOption(
argList:List[String],
map:Map[String, String]
) : Map[String, String] = {
val pattern = "--(\\w+)".r // Selects Arg from --Arg
val patternSwitch = "-(\\w+)".r // Selects Arg from -Arg
argList match {
case Nil => map
case pattern(opt) :: value :: tail => nextOption( tail, map ++ Map(opt->value) )
case patternSwitch(opt) :: tail => nextOption( tail, map ++ Map(opt->null) )
case string :: Nil => map ++ Map(string->null)
case option :: tail => {
println("Unknown option:"+option)
sys.exit(1)
}
}
}
nextOption(args.toList,Map())
}
例子:
val args=Array("--testing1","testing1","-a","-b","--c","d","test2")
argsToOptionMap( args )
给:
res0: Map[String,String] = Map(testing1 -> testing1, a -> null, b -> null, c -> d, test2 -> null)